Electrochemical Behavior of Sparfloxacin at SWCNT-film Modified Glassy Carbon Electrode and Its Application to the Determination of Sparfloxacin

Electrochemical behavior of sparfloxacin (SPFX) at the single wall carbon nanotube (SWCNT) film modified glassy carbon electrode (GCE) was studied thoroughly by cyclic voltammetry and linear sweeping voltammetry.In a 0.1 mol·L-1 Na2HPO4-NaH2PO4 buffer solution of pH 6.0,a well-defined oxidation peak was observed at 1.06 V,and linear relationships between values of oxidation peak current and concentration of SPFX were obtained in 2 range sections,i.e.,from 1.1×10-6 to 2.2×10-5mol·L-1 and from 2.7×10-5 to 1.6×10-4mol·L-1.Detection limit (3S/N) of the method found under the condition of open-circuit accumulation for 30 s was 5.0×10-7mol·L-1.Adsorbed substances on the surface of the modified electrode were removed by cyclic voltammetric sweeping and thus making the electrode activity recovered.Ten determinations of SPFX with a same electrode at the concentration level of 4.0×10-5mol·L-1 were made to test for its precision,giving value of relative standard deviation of 5.1%.In analyzing a sample of SPFX tablet by the proposed method,the results obtained were in consistency with the labelled value.Test for recovery was made by the standard addition method based on the matrix of tablet sample,values of recovery found were in the range of 97.6%-105.7%.